The present invention relates to a self-emission panel and a method of fabricating the same.
The present application claims priority from Japanese Application No. 2005-291353, the disclosure of which is incorporated herein by reference.
A self-emission panel 10J such as an organic EL (electroluminescent) panel includes one or more self-emission elements 1J, as shown in FIG. 1A. The self-emission element 1J has the structure that a lower electrode 12J is formed on a substrate 11J directly or through other layers, a deposition layer (luminescent functional layer) 13J is laminated on the lower electrode 12J, and an upper electrode 14J is formed on the deposition layer 13J. Electrons are injected from a cathode side formed on one of the lower electrode 12J and the upper electrode 14J, and holes are injected from an anode side formed on the other of the lower electrode 12J and the upper electrode 14J. The electrons and holes are recombined in the deposition layer 13J or the like for light emission. A conventional self-emission panel 10J is provided with a sealing member for sealing the self-emission elements 1J to protect the deposition layers 13J from moisture.
In a conventional passive driving type self-emission panel 10J, cathode lines (upper electrodes 14J) L1˜Lm are formed in a lateral direction on a panel section 1b, and anode lines (lower electrodes 12J) A1˜An are formed in a longitudinal direction, as shown in FIG. 1B. The self-emission elements 1J are formed on positions corresponding to intersections of the cathode lines L1˜Lm and the anode lines (lower electrodes) A1˜An. One end of the self-emission element 1J is connected with the cathode line, and the other end thereof is connected with the anode line. For instance, the cathode lines (upper electrodes) L1˜Lm are connected with a scanning driver 1c, and the anode lines A1˜An are connected with a data driver 1d. The scanning driver 1c and the data driver 1d are controlled by a control section 1e. 
In recent years, the self-emission panels are required to lower their power consumption as the self-emission panels grow larger in size. Several techniques are known as a method for reducing the power consumption. For example, PCT International Application publication No. 2000-60907 discloses an organic electroluminescence display device in which auxiliary wiring layers are electrically connected with lower electrodes formed on a substrate.
It is, however, difficult to achieve the low power consumption of the self-emission panel in a larger size, even if the auxiliary wiring layers are formed on the lower electrodes to reduce the electrical resistance of the lower electrodes, as in the display device mentioned above. Therefore, it is required to achieve the low electrical resistance of upper electrodes.
When the electrical resistance of the upper electrodes is to be reduced simply by increasing the film thickness of the upper electrodes, there can be defective deposition including occurrence of microscopic projections called hillock, or the like.
The self-emission panel 10J having the large-size panel section 1b can have the following problem when the cathode lines (upper electrodes 14J) have high electrical resistance. As shown in FIG. 1C, the self-emission elements 1J of the panel section 1b adjacent to the scanning driver 1c are applied with a voltage VH. On the other hand, the self-emission elements 1J located farther from the scanning driver 1c are applied with less voltage due to voltage drop, resulting in a low voltage VL. For this reason, the large-size self-emission panel 10J can have an irregularity in an emission brightness, such as an emission brightness inclination. That is, the self-emission elements 1J closer to the scanning driver 1c have a higher emission brightness, while the self-emission elements 1J located farther from the scanning driver 1c have a lower emission brightness.